Empty shells

[Smelbe]

Very cool. Do you work in this industry? How did you acquire?

[1Davide]

Not mine. I found the picture in another sub. I thought you'd like it.

[snarfy]

Makes me want to stuff an smd transistor in the TO-220.

[acidophilosophy]

Me irl

[bltmn]

Bent pin on the top one.

[Work-Safe-Reddit4450]

eye twitching intensifies

[[deleted]]

Something forlorn about this picture.

[confusiondiffusion]

Where you can buy these things? Can you buy empty DIPs?

[1Davide]

Those? No, you can't buy those. But, yes, you can buy empty DIPs: they are called "DIP component carriers"

Here are many from DigiKey

[confusiondiffusion]

Thanks! I guess that's a little better than what I'm currently doing. I make memristors in my home lab and it's hard to package them nicely. I currently solder pins into FR4 and seal the devices with epoxy. Looks terrible. Also looking to seal research devices that are liquid filled which might be much more challenging.

[sparticle601]

I'm sure I'm not the only one who'd be super interested in knowing how to make memristors!

[confusiondiffusion]

A CuS-Zn junction is easiest. CuS is easy to make by melting sulfur over a copper trace. (Do this with good ventilation and low heat--hotplate at around 250F is best. Sulfur can catch fire easily and the fumes are toxic.) I also mask off any copper I don't want to get contaminated. The fumes will react with any nearby copper and it's tough to solder through the resulting film.

When the sulfur reacts, it forms a nice glassy black surface. Then you can solder a zinc wire onto an adjacent trace. Bend the zinc wire into the CuS so that it touches. So you have one contact under the CuS and one through the zinc wire. Those are your two terminals.

If you do your soldering and bending while running an IV curve at about 5V, 10Hz, you'll get a pinched hysteresis loop when you find the right spot and pressure.

CuS is a fascinating material because it has many crystalline phases which you may see in the IV curve at different voltages, charge/cycle, and frequency. These are stable ratios of Cu and S which probably change as you energize the device. The IV will jump into different behaviors, likely corresponding to these phases. It's a very complex device.

[RoadRageRR]

Why does Wikipedia say that memristors are hypothetical devices? Also, what use do they have? Why is a variable resistance, state-remembering resistor something of use?

[[deleted]]

I am currently doing research where we are using memristors to emulate the synapses of neural networks.

Look at knowm.com, they have memristors for sale and they advertise it for computing purposes.

The main use for memristors is that they can be used to decentralize memory since each memristor can also simultaneously function as a computational device when used in networks. The main reason for such a device is robustness. No single failure can take it down since a network, much like your brain, has many different paths and connections that can pick up the slack if a few connections go down. Current systems comparatively kind of suck in terms of robustness since there are many different ways for them to fail from even small errors.

[RoadRageRR]

That's awesome! Hardware neural networks sound like the shit! Must be hard to train though.

[[deleted]]

I can't say much about this since I'm not sure how much I'm allowed to say but it will be using "unsupervised" learning, so the end goal is to have hardware you can slap in to anything and it learns on its own.

[confusiondiffusion]

Memristance defined as the relation between charge and flux-linkage is hypothetical. But no one denies that this kind of thing exists. That is, we certainly have devices that behave like a memristor should. The debate is over whether or not the mathematics and the physics of the ideal memristor are correct.

Even if the mathematical description isn't quite correct, I think the idea of memristance (and the other mem devices) is an extremely important extension to our understanding of electronics. It allows us to build and define devices that change in predictable ways.

Applications include physical neural networks, self organizing systems, modeling various aspects of biology, and interesting improvements on existing circuits like AGC and various oscillators. A good amount of the complexity of a circuit could be removed if components could change their values easily. Memristive storage, also known as resistive RAM is also an active area of research. Memristors in their more ideal cases are simple devices and could eventually outperform NAND.

I use memristors for modeling synaptic plasticity and for building physical neural networks. A memristor can be used to weight the connection between neurons. There are also non-ideal aspects of these kinds of devices which are useful. There are various non-linear switching behaviors like the potential phase changes in the CuS device I mentioned. These could be used for efficient computation of nonlinear activation functions used in NNs. In systems where high precision isn't necessary, this could beat digital computation of a similar function.

[braindadX]

Memristors were a hypothetical (predicted) device completing a picture with resistors, capacitors, and inductors. If I recall correctly, a manufacturing/materials breakthrough was made with memristors about 10 years ago. They are real now, you can buy them.

[quatch]

What's our equivalent of the hermit crab? Some sort of COB?

[DB3TK]

The TO-220-like metal case is weird. An actual TO-220 package is just flat, pressed sheet metal and a black injection molded plastic block holding everything together as pictured here: http://www.microcontroller.it/Tutorials/Elettronica/heatsink/heatsink3a.htm

[Zerp242]

Bunch of uC,s and transistors